Biomedical subjects

Michel Isingrini

Publications and source records attributed to Michel Isingrini.

At least 19 recordsLinked to original sources

PubMed2006

Diminished episodic memory awareness in older adults: evidence from feeling-of-knowing and recollection.

The ability to reflect on and monitor memory processes is one of the most investigated metamemory functions, and one of the important ways consciousnesses interacts with memory. The feeling-of-knowing (FOK) is one task used to evaluate individual's capacity to monitor their memory. We examined this reflective function of metacognition in older adults. We explored the contribution of metacognition to episodic memory impairment, in relation to the idea that older adults show a reduction in memory awareness characteristic of episodic memory. A first experiment showed that age affects the accuracy of FOK when predictions are made on an episodic memory task but not on a semantic memory task, suggesting a particular role for episodic memory awareness in metacognitive evaluations. A second experiment showed that the age-difference in episodic FOK accuracy was removed if one took into account subjective reports of memory awareness, or recollection. We argue that the FOK deficit specific to episodic memory is based on a lack of memory awareness manifest as a recollection deficit.

Adult↗

PubMed2006

Aging and strategic retrieval in a cued-recall test: the role of executive functions and fluid intelligence.

Cued-recall in episodic memory was investigated in relation to low and high cognitive support at retrieval, executive function level and fluid intelligence level in 81 healthy adults divided first into two age groups (young and elderly adults). The first analyses showed that age-related differences were greater when a low cognitive support was provided to recall the words. An individual index of loss of performance when the number of cues was decreased was then calculated. Hierarchical regression analysis revealed that the executive functions measure (perseverative errors on the Wisconsin Card Sorting Test) was a better candidate than the fluid intelligence measure (Cattell's culture fair test) to account for the age-related variance of the size of performance loss. These findings suggest that age differences in implementing strategic retrieval may be mainly due to a decline in executive functions.

Adult↗

PubMed2006

Age-related changes in duration reproduction: involvement of working memory processes.

The aim of the present research was to study age-related changes in duration reproduction by differentiating the working memory processes underlying this time estimation task. We compared performances of young and elderly adults in a duration reproduction task performed in simple and concurrent task conditions. Participants were also administered working memory tests to measure storage and central executive functions. Findings indicated a differential involvement of working memory storage and central executive functions in age-related differences in temporal tasks. The limited storage capacities explained age-related changes in the simple task of duration reproduction, and the dysfunctioning of central executive functions accounted for age-related changes in duration reproduction performed in a concurrent task condition, which involves greater attentional resources.

Adult↗

PubMed2006

Autobiographical memory, autonoetic consciousness, and self-perspective in aging.

In this study, the authors examined the effects of aging on autobiographical memory in 180 participants by means of a new method designed to assess across 5 lifetime periods the nature of memories-that is, specificity and spontaneity--and the phenomenal experience of remembering--that is, self-perspective and autonoetic consciousness--via the field/observer and remember/know paradigms respectively. Age-related differences were found for the specificity and spontaneity of memories and the phenomenal experience of remembering. There was an increase in observer and know responses with age, but a decrease in field and remember responses and in the ability to justify them by recalling sensory-perceptive, affective, or spatiotemporal specific details. This pattern confirms the existence of a semantic-episodic dissociation in autobiographical memory in aging. Moreover, the data support the view that older participants can subjectively "travel back in time" to relive personal events in the most distant past better than those in the recent past.

Adult↗

PubMed2006

Aging and implementation of encoding strategies in the generation of rhymes: the role of executive functions.

This experiment examines whether the age-related decrease in the generation effect of rhymes is mediated by executive functioning. Young and elderly adults read and generated pairs of rhyming words for subsequent recall. Participants were also administered neuropsychological tests (executive and mnemonic functions). Results showed that elderly adults performed less well on the neuropsychological tests and benefited less than the younger participants from the generation effect. Hierarchical regression analyses revealed that the executive functions composite score was correlated with the generation effect and that it accounted for a large proportion of the age-related variance of the size of this measure. This finding supports the view that the age-related decrement in strategic encoding implementation is due to a decrease of executive functioning.

Adult↗

PubMed2006

Trauma-related deficits in working memory.

INTRODUCTION: The aim of the study was to evaluate trauma-related impairments of working memory in psychiatric outpatients, and the mediating role of processing speed, anxiety and depression in the cognitive decrements. METHODS: This research applied a comprehensive assessment protocol including an evaluation of psychopathological and neuropsychological functioning in psychiatric outpatients. Patients with trauma history (n = 33) were compared to patients without such a history (n = 30). We collected information regarding age, gender, culture level, profession level, alcohol abuse, anxiety, and depression symptoms. Working memory and speed processing were assessed with standardised neuropsychological instruments. Data analysis was accomplished using parametric statistics, and a hierarchical multiple regression model was used to regress working memory performance scores against the trauma variable, anxiety-depression scores, and speed processing. RESULTS: The groups differed by gender, not by age, education level, socioeconomic status and alcohol abuse. Analysis of cognitive data revealed specific trauma-related deficits in working memory. Moreover, the trauma-exposed subjects scored higher on anxiety/depression scales, and lower on processing speed tests. The regression revealed significant impairment in working memory partially mediated by speed processing, but not by anxiety or depression. CONCLUSIONS: These findings confirmed the trauma-related impairments in working memory and the paramount importance for these impairments of reduced processing speed rather than emotional factors.

Adolescent↗

PubMed2006

Metamemory monitoring and Parkinson's disease.

Feeling-of-knowing (FOK) and global prediction in episodic memory were examined in 16 patients with Parkinson's disease (PD) and 16 elderly control subjects. Subjects were given cued recall and recognition tests of 20 critical cue-target words. Prior to the study phase, participants were asked to predict the number of words they could recall. During the recall phase, they judged their FOK for non-recalled words in terms of how likely they thought they would be able to recognize the key words on a subsequent recognition test. No difference was found in the two groups for global prediction accuracy. However in comparison to the older adults, PD patients exhibit impaired FOK accuracy, suggesting that in some circumstances metamemory may be altered in Parkinson's disease.

Aged↗

PubMed2005

Episodic feeling-of-knowing accuracy and cued recall in the elderly: evidence for double dissociation involving executive functioning and processing speed.

This research investigated adult age differences in a metamemory monitoring task-episodic feeling-of-knowing (FOK) and in an episodic memory task-cued recall. Executive functioning and processing speed were examined as mediators of these age differences. Young and elderly adults were administered an episodic FOK task, a cued recall task, executive tests and speed tests. Age-related decline was observed on all the measures. Correlation analyses revealed a pattern of double dissociation which indicates a specific relationship between executive score and FOK accuracy, and between speed score and cued recall. When executive functioning and processing speed were evaluated concurrently on FOK and cued recall variables, hierarchical regression analyses showed that executive score was a better mediator of age-related variance in FOK, and that speed score was the better mediator of age-related variance in cued recall.

Adult↗

PubMed2005

Differential involvement of internal clock and working memory in the production and reproduction of duration: a study on older adults.

The present study uses the inter-individual variability in time perception of a group of elderly participants to differentiate the processes underlying time production and time reproduction. Participants performed duration production and reproduction tasks. They were also administered working memory tests and a spontaneous motor tempo task. The findings suggest that duration production and duration reproduction involve different mechanisms. Correlational analyses revealed a double dissociation: production was only correlated with spontaneous motor tempo and reproduction only with working memory measures. These findings suggest that the internal clock rate modulates the production of duration and that reproduced duration varies according to working memory capacities.

Aged↗

PubMed2005

Neural correlates of word-stem priming.

The purpose of this study was to identify the neural correlates of implicit memory in a word-stem completion task. Given that both explicit and implicit retrieval tend to occur in this type of memory task, conventional analyses of old/new event-related potential effects are equivocal. To overcome this problem, depth of processing was manipulated and subjective awareness measured. From 400 ms poststimulus, event-related potentials evoked by stems completed with studied words were more positive than those evoked by stems completed with unstudied items. This difference was maximal at parietooccipital electrode sites. Event-related potentials were not modulated by either depth of processing or awareness. Behavioral and event-related potential data converged to indicate that the old/new effect reflects processes either contributing to, or contingent upon, implicit memory retrieval.

Adult↗

PubMed2005

The effect of encoding manipulation on word-stem cued recall: an event-related potential study.

The purpose of the present study was to find out whether the neural correlates of explicit retrieval from episodic memory would vary according to conditions at encoding when the words were presented in separate study/test blocks. Event-related potentials (ERPs) were recorded while participants performed a word-stem cued-recall task. Deeply (semantically) studied words were associated with higher levels of recall and faster response times than shallowly (lexically) studied words. Robust ERP old/new effects were observed for each encoding condition. They varied in magnitude, being largest in the semantic condition. As expected, scalp distributions also differed: for deeply studied words, the old/new effect resembled that found in previous ERP studies of word-stem cued-recall tasks (parietal and right frontal effects, between 400-800 and 800-1100 ms post-stimulus), whereas for shallowly studied words, the parietal old/new effect was absent in the latter latency window. These results can be interpreted as reflecting access to different kinds of memory representation depending on the nature of the processing engaged during encoding. Furthermore, differences in the ERPs elicited by new items indicate that subjects adopted different processing strategies in the test blocks following each encoding condition.

Adult↗

PubMed2005

Does priming with awareness reflect explicit contamination? An approach with a response-time measure in word-stem completion.

The present experiment investigates the involvement of awareness in functional dissociations between explicit and implicit tests. In the explicit condition, participants attempted to recall lexically or semantically studied words using word stems. In the implicit condition, they were instructed to complete each stem with the first word which came to mind. Subjective awareness was subsequently measured on an item-by-item basis. As voluntary retrieval strategies are known to be time consuming, the time taken to complete each stem was recorded. In the explicit task, semantically studied words were associated with higher levels of recall and faster response times than lexically studied words. By contrast, in the implicit task, these effects failed to reach significance, although deep encoding made the contents of memory more accessible to awareness. As expected, performance was slower in the explicit than in the implicit task, but in the latter condition, times to produce old words with and without awareness were comparable, and both of these responses were produced more quickly than control words. This finding suggests that although participants may become aware in implicit paradigms, they do not adopt voluntary retrieval strategies.

Adult↗

PubMed2005

Updating information in verbal working memory and executive functioning.

50 older adults (M age=77.9 yr., SD=7.3; 35 women and 15 men) were tested using the updating working-memory task. They were also given the neuropsychological Wisconsin Card Sorting Test, assumed to evaluate executive functioning and the frontal cortex. A factor analysis with age, education, and verbal ability partialled out was computed on the updating task outcomes and resulted in a two-factor solution, indicating that this task requires two independent processes, interpreted as reflecting a storage component and an updating component. Partial correlations with age, education, and verbal ability partialled out indicated that Wisconsin Card Sorting Test measures were significantly associated with the factor supposed to reflect the updating process. Such results appeared consistent with the model of working memory with a central executive system involved in the updating process and related to the executive-frontal functioning, and a phonological loop system involved in the storage of verbal information and not linked to executive-frontal functions.

Aged↗

PubMed2004

Age related differences in metacognitive control: role of executive functioning.

To examine whether aging affects metacognitive control, elderly and young adults carried out a readiness-recall task, in which subjects monitor their own learning procedure, allowing strategy manipulation (study time and rehearsal) to be measured. Age differences were observed in metamemory control performance. Younger adults were found to be better at adjusting study time and rehearsal to the task. Moreover, to determine whether age-related differences in strategy manipulation may mediate age-related differences in memory performance, performance on the readiness-recall task was compared to performance on an experimenter-paced task. Results indicated that younger adults recalled significantly more words in the readiness-recall task than in the experimenter test. This was not the case for older adults. Furthermore, a hierarchical regression analysis revealed that age-related differences in strategy manipulation mediate some age-related differences in memory performance. Our aim was also to determine whether metacognitive control is related to executive functions. Thus, all participants were administered standard neuropsychological tests used to assess executive functioning. Significant partial correlation appeared between metamemory control and executive functioning. Finally, a hierarchical regression analysis indicated that age-related decline in metamemory control may be largely the result of executive limitations associated with aging.

Adult↗

PubMed2004

Cognitive operations in the generation effect on a recall test: role of aging and divided attention.

Generation effect (generated words are better memorized than read words) of anagrams, rhymes, and associates of target words was examined in young, elderly, and very old subjects. Experiments 1 and 2 showed that only young subjects benefit from the generation effect in a free-recall test when the rule is of a phonological nature. Experiments 3, 4, and 5 showed that the generation effect of rhymes was due to a resources-dependent self-initiated process. Experiments 4 and 5 showed that in a divided-attention situation, generation effect of rhymes is not significant in young subjects, but that the generation effect of semantic associates remains significant for both groups (Experiment 5). The results are discussed within the environmental support framework and the transfer-appropriate processing framework.

Adult↗

PubMed2003

Metamemory accuracy in Alzheimer's disease and frontotemporal lobe dementia.

Metamemory is a multifaceted concept, which deals with an individual's knowledge and control of his or her own memory system. The ability to monitor memory performance accurately was examined in 16 patients with Alzheimer's disease (AD), 6 patients with frontotemporal lobe dementia (FTD) and 16 elderly subjects. Participants made global memory predictions in a single experimental task, both prior to and after studying 20 critical cue-target words. Prediction accuracy was evaluated with traditional score-difference measures. Our data showed that in the case of the after-study prediction FTD patients were more inaccurate in predicting their memory performance than were the AD patients, suggesting that FTD patients were more impaired than AD patients in monitoring their memory performance. Nevertheless, there seems to be no difference regarding their metacognitive knowledge or beliefs of their own memory, as indicated by the absence of difference in prediction accuracy made before study. Moreover, analyses of covariance showed that the difference in metamemory performance between AD and FTD may be related to the executive differences observed in these two populations. In sum, our results suggest that metamemory evaluation could be useful to distinguish between patients with AD and those with FTD.

Aged↗

PubMed2003

[Differential effects of aging on processes involved in mental imagery generation].

The purpose of this study was to measure the degree to which the deterioration of mental image generation processes observed in elderly subjects by Dror and Kosslyn (1994) depends on the nature of the processing (referential vs. representational) involved in performing the task at hand. In keeping with the results of research showing that processing resources diminish as normal aging occurs (Craik & Bird, 1982; Rabinowitz, Craik & Ackerman, 1982), we suggest that generation ability based on referential processing is affected to a greater extent in older adults than is the generation ability involving representational processing. Fifteen young adults and 15 elderly persons performed a generation task modeled on that used by Dror and Kosslyn (1994). Observations were based on two contrasting conditions. In the first instance, subjects were required to generate an image representation of numbers when instructed to do so by a graphic stimulus, e.g., "31" (representational generation). In the second case, generation was produced on the basis of a verbal stimulus, e.g., "thirteen" (referential generation). Results (response time and number of accurate answers) show that, compared to young adults, elderly adults have a diminished ability to generate images based on words rather than numbers and do so at a slower pace. Our results suggest, therefore, that the performance of the first type of generation is cognitively more demanding for elderly subjects than that which is founded on figurative stimuli. The deterioration of mental image generation processes observed in elderly subjects by Dror and Kosslyn (1994) is therefore dependent on the nature of processing (referential vs. In conclusion we suggest two complementary assumptions to explain the observed dissociation. The differential effect of age may be the result of a deficienness cy linked to the nature of processing (control vs. automatic). Our second assumption is that, more specifically, referential generation involves more processing resources than does representational generation because it requires an additional transcoding operation. In this instance, the differential effect of aging that we observed would be closely linked to the number of cognitive operations involved in mental image generation.

Adult↗

PubMed2002

Mediators of age-related differences in recollective experience in recognition memory.

This study examined states of awareness with the Remember/Know paradigm during verbal recognition memory in young and old adults. Following the presentation of a word list, subjects undertook a recognition test and indicated whether they could consciously recollect its prior occurrence (R) or recognize it on some other basis, without conscious recollection (K). In this individual-difference approach we also incorporated various processing-speed and working-memory measures to study the link between aging, states of awareness and processing resources. The results revealed that, compared to younger adults, older adults exhibited a decline in the amount of R responses during the recognition test whereas the amount of K responses did not change. Structural equation modeling indicated that a slower processing speed associated with a limited working-memory capacity is a key to explaining age-related variance in conscious recollection. The findings offer further support for the distinction between remembering and knowing and for the processing-resources hypothesis of aging.

Adult↗